1. Field of the Invention
The present invention relates to a component supply method for obtaining individual components by cutting a wafer of ceramic or silicon, for example, and supplying the as-obtained individual components to a subsequent processing step.
2. Description of the Background Art
In relation to a technique of obtaining a number of silicon chips from a silicon wafer, the following two methods are well known in the art:
In the first method, an adhesive sheet which is provided on its one surface with an adhesive layer whose adhesion can be reduced by irradiation with ultraviolet rays is prepared. As shown in FIG. 2, a wafer 2 is stuck onto a surface of such an adhesive sheet 1 provided with an adhesive layer. Then, the wafer 2 is diced to be subdivided into individual silicon chips 3. Then, ultraviolet rays are applied to reduce adhesion of the adhesive layer provided on the adhesive sheet 1. Thereafter the adhesive sheet 1 is mounted on an expander which is carried on an X-Y drive unit. Then, the adhesive sheet 1 is expanded by the expander so that its area is enlarged as shown in FIGS. 3A and 3B, thereby separating the respective silicon chips 3 from each other. Referring to FIGS. 3A and 3B, the adhesive sheet 1 is mounted on adhesive sheet mounting members 4 which are provided in the expander.
When the silicon chips 3 are separated from each other through clearances as described above, positional information of each silicon chip 3 is obtained through an image taken by a camera on the adhesive sheet 1, and the X-Y drive unit is driven on the basis of such positional information to locate the silicon chip 3 to be taken out on a chip discharge position.
On the other hand, a thrust pin 5 is arranged under such a chip discharge position as shown in FIG. 4, while a suction chuck 6 is arranged above the silicon chip 3. In this chip discharge position, the thrust pin 5 is upwardly driven as shown in FIG. 4 to upwardly move the silicon chip 3 to be removed, so that this silicon chip 3 is sucked by the suction chuck 6 in this state and carried to be supplied to a next step.
The second method utilizes a foam releasable adhesive sheet, which is formed by a base material having a foam releasable adhesive layer, whose adhesion can be reduced by heating, provided on one surface and another adhesive layer, whose adhesion can not be reduced by heating, provided on another surface. In the second method, the adhesive layer provided on the other side of such a foam releasable adhesive sheet is stuck onto a flat plate type support member to expose the foam releasable adhesive layer, so that a silicon wafer is stuck onto the foam releasable adhesive layer and diced to be subdivided into individual silicon chips. Then the plate type support member is heated to reduce the adhesion of the foam releasable adhesive layer, and the respective silicon chips are separated from this layer at random to obtain a number of silicon chips.
In the first method, each silicon chip is located in the discharge position through image processing. Therefore, a high-priced image processor is required and it takes time for such processing, leading to insufficient component suppliability. Further, the thrust pin 5 is so worn upon repeated employment that the same must be replaced by a new one. In addition, the silicon chip 3 may be damaged by impact applied by the thrust pin 5.
On the other hand, the second method can be carried out at a low cost since no image processor is required. In this method, however, the adhesion of the foam releasable adhesive layer is reduced by heating to separate a number of silicon chips from this layer at random. In order to systematically supply such silicon chips to a next step, therefore, it is necessary to realign the as-obtained number of silicon chips with a complicated operation.